<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>Flex Layout</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="layout.css">
</head>
<body>
    <nav>Nav</nav>
    <article>
        <aside>Left</aside>
        <section>Content</section>
        <aside>Rihgt</aside>
    </article>
    <footer>
        Footer
    </footer>
</body>
</html>